relax SVN archive

Improvements to the Scientific Python structural object atom_loop() method.

Multiple molecules of different types are now simultaneously supported.

Fix for the print out of the load_spins() function.

Now only when a new SpinContainer is created is the spin system information written to stdout.

Bug fix for the write_line() function.

Added the missing import of generic_fns.sequence.write_line().

Updated the load_spins() function to print out a list of spins appended to the data store.

Fix for the test_angles() system test. The spins are now loaded.

Bug fix, the diffusion_tensor.init() fixed flag is now a bool.

Bug fix, the diffusion_tensor.init() fixed flag is now a bool.

Converted the read() function to the new relax design.

Converted the get_specific_fn() raise_error arg to a bool.